Review: Magnificent Ledger's tour de force gives this complex film its energy

We get a taster of this mutilated psychopath's amoral methods, as much terrorist as criminal, in the opening bank robbery sequence. Then the narrative snaps to Bale's Batman, who is troubled by copycat vigilantes, and wondering whether he should make way for crusading DA Harvey Dent (Aaron Eckhardt), who has already won the heart of his childhood sweetheart Rachel (Maggie Gyllenhaal). Unfortunately the Joker, backed by Mob money, is on a mission to prove that Gotham's a writhing pit of iniquity, where no one is reliably safe, sane, or good. He and Batman engage in a struggle for the city's soul.

Nolan smuggles complex issues of identity and the limits of morality into the cracking set-piece confrontations between the two costumed oddballs, who are flipsides of the same coin. He also equips Bale with some great new toys, a mordant wit to undercut the story's essential bleakness, and a trio of advisers: Michael Caine's butler Alfred, Gary Oldman's good cop Jim Gordon and Morgan Freeman's weapons-master Lucius Fox. The pace sags and the story falters only slightly towards the end, before a satisfyingly grim climax that sets up the next film.

And Ledger? Although the Joker's menace is anonymous, random and impersonal, meaning this is more of a star turn than a performance, he's magnificently creepy and unhinged. His manic zest gives the film its energy. He knocks Jack Nicholson into a cocked purple hat. Even if he doesn't get that posthumous Oscar, this is enough of a tour de force to make us mourn him again.